A user device may be associated with a user device identifier, such as a phone number, an email address, a network address, or the like. Some user devices may be associated with two or more user device identifiers, and such user devices may permit a user to access a network service in relation to the two or more user device identifiers. For example, a user device may select a particular user device identifier, of the two or more user device identifiers, for accessing a particular network service.